Question

The IUPAC name of \( \text{CH}_3\text{CH}_2\text{CH}_2\text{OH} \) is

• A. 2-methyl-1-propanal
• B. Isobutyl alcohol
• C. 2-methyl-1-butanol
• D. None of these

Hint:

In IUPAC nomenclature, the longest chain is identified first, and the substituents are numbered to give the lowest possible locants for the functional group.

Answer 1

The Correct Option is C

Step 1: Understanding the IUPAC naming.
The molecule \( \text{CH}_3\text{CH}_2\text{CH}_2\text{OH} \) is a butanol with a methyl group on the second carbon. In IUPAC nomenclature, we first identify the longest chain, then number it such that the hydroxyl group is on the lowest possible numbered carbon. Step 2: Analysis of options.
(A) 2-methyl-1-propanal: This is incorrect because "propanal" indicates an aldehyde, not an alcohol.
(B) Isobutyl alcohol: This is incorrect because the structure is not an isobutyl group.
(C) 2-methyl-1-butanol: Correct — This is the correct IUPAC name, as it reflects the hydroxyl group on the first carbon and a methyl group on the second.
(D) None of these: This is incorrect because option (C) is correct.
Step 3: Conclusion.
The correct answer is (C) because the IUPAC name for \( \text{CH}_3\text{CH}_2\text{CH}_2\text{OH} \) is 2-methyl-1-butanol.